i'm NOT worried about erectile dysfunction... never had a problem with that.
i had an accident at a young age that required surgery, and i was told about my muscle control then.
when your pc muscles are strong, here's what you can do:
1. as a man, you can STOP your flow of urine. period. many don't believe that men can do this, but i can. when/if you can achieve that, you KNOW your pc muscles are strong. start pissing and stop it. a few drips and then nothing. then, start it up again.

you don't need to do this for anything except to TEST your muscle strength. i had to do it as part of my therapy from the surgery i had as a kid.
2. you can STOP yourself from busting a nut. remember when you were a teenager, and they taught you the pull out and squeeze with your hand to stop the nut? well, with strong pc muscles, i can keep stroking while squeezing my pc muscle... delaying the nut until I am ready to bust. before i was this strong, like 16 or 17 yrs old, i had to use the hand method. now, as a card-carrying bonafide older dicksman, i just bury the dick at the bottom, flex (throb) a few times for the lady's pleasure, then, squeeze hard to make sure i don't nut.
it's called DICK CONTROL = PEEEEEENUS power = i will TAKE your woman from you.
when i was younger, i could do this shit all night... delaying the nut until she either said, "i quit," or the pussy went dry. but now, at 38, i hang around until she gets hers, then, i bust mine, and fuck dat... a nigra is going to sleep.